1. Field of the Invention
The present invention relates to a frequency synthesised multichannel radio apparatus.
2. Field of the Invention
A frequency synthesised multichannel radio apparatus is known in which data to be supplied to the synthesiser to the apparatus is stored in a programmable storage means (PSM) such as a programmable read only memory (PROM) mounted in a transceiver. Data to be read-out of the PSM is selected in response to the PSM being suitably addressed by means of a manually operable channel selector in a remotely mounted control unit directly supplying the selected address to the PSM. The allocation of receiver and transmitter frequencies to any channel is fixed for the PSM, these frequencies being paired for each channel.
A drawback to such an arrangement is that if it is desired to change the allocation of frequencies to channels then it is necessary, in the case of a PROM, to remove the PROM from the transceiver and replace it with a PROM which has been programmed/reprogrammed with the new allocation of frequencies to the channels. This type of operation can be costly as well as time consuming especially when setting-up a national radio system formed by a plurality of regions some of which overlap so that the radio apparatus in one region must be capable of receiving from, and transmitting to, apparatus in an adjoining region.